My computer is three years old. Recently I just added a 2GB RAM onto the second and final socket. I'm thinking about adding more memory just in case, but many sites suggest that my motherboard- p5kpl-am se - can only support maximum of 4GB of RAM. Right now I have 4GB of RAM distributed in two sockets, can I replace one memory stick with a 4GB memory stick and bump the total RAM up to 6GB or more for this specific motherboard? Thanks!